Priority quality traits for gendered sweetpotato breeding in Mozambique

IntroductionSweetpotato breeders strive to develop varieties that address productivity challenges farmers face in sub-Saharan Africa (SSA). However, adoption of these varieties is low, partly attributed to limited attention to attributes desired by the end-users.MethodsThis study sought to identify the key traits preferred by eight women processors and 426 consumers (180 male, 246 female) in Manhiça, Marracuene and Maputo districts, Mozambique. Processing diagnostics and consumer studies evaluated two local varieties (‘Lilas’, ‘N’santimuni’) and two improved varieties (‘Alisha’, ‘Irene’). Data from processors were analyzed using content analysis and summary statistics. Consumer hedonic data were analyzed using clustering and regression models, while Penalty analysis and Multiple correspondence analysis were performed for the Just-about-right and Check-all-that-apply tests respectively.ResultsProcessors prioritized mealiness, sweet taste, not fibrous, good sweetpotato smell, ease of peeling, easy to cook and good appearance for the boiled root. ‘N’santimuni’ was the most preferred variety for processing. Consumers preferred ‘N’santimuni’ and ‘Lilas’ because of their high dry matter, pleasant sweetpotato smell, firmness in the hand, smoothness when eating and sweet taste. ‘Alisha’ and ‘Irene’ were the most penalized for low scores on sweetness, mealiness, and firmness. Women consumed sweetpotato more frequently than men and had better discernment of sweet taste, homogeneity and colour. Also, youth and more educated consumers disliked improved varieties more than adults and lower income consumers.DiscussionProcessors and consumers strongly indicated their preference and importance of quality attributes such as mealiness, sweet taste, firmness for boiled sweetpotato. However, such traits are rarely included in breeding designs. Breeding programs can thus be enhanced by studies of biophysical and chemical parameters of sweetpotato. This will enable quantification incorporation of these quality attributes

Crop Ontology Governance and Stewardship Framework

A governance & stewardship framework for the Crop Ontology Project is required as this is a collaborative tool developed by a Community of Practice. Over the last 12 years of its existence, it has increased significantly in scope and use. Collecting and storing plant trait data and annotating the data with ontology terms is widely accepted by the crop science community to be critical to enable data interoperability and interexchange through tools such as the Breeding API (BrAPI). The Crop Ontology Community of Practice is organised around roles, curation principles and validation processes that require a formal description. A governance framework is defined by the various actors involved in the asset’s design, development and maintenance. It is complemented by a quality assurance process to ensure that trust levels, value creation, and sustainability objectives meet appropriate quality levels. The general principles underlying data governance are integrity, transparency, accountability and ownership, stewardship, standardization, change management and a robust data audit

Climate Change: A Real Danger to Human and Animal Survival

Some countries in Southern Africa where hit by either a storm or cyclone or both in 2019 alone manifesting a changing climate. Infrastructure and cropping land was destroyed, both animal and human lives were lost due to the flooding events. Drought is a common phenomenon in this region, often occurring once in three years. This has affected food, feed and nutritional security of both humans and livestock. Saline soils unsuitable for agriculture, other animal and plant life are expanding fast due to insufficient precipitation. Soil degradation is on the rise, leaving soils with poor water holding capacity to support sustainable agriculture. Climate change is changing the environment and new pests and diseases for both crops and livestock are emerging. World governments, industries and general populace should find better ways of reducing air pollution by greenhouse gases which have a net effect of damaging the ozone layer and increasing atmospheric temperatures. At the same time, plant and animal breeding should aim at improving crop cultivars and animal breeds that resist to the constraints such as drought and heat stress brought by climate change. The human population is increasing at an alarming rate and need both food and nutritional security

Adapting sweetpotato production to changing climate in Mozambique

Vines are the major source of planting material in sweetpotato. Extended dry spells hinder conservation of vines and in turn affect the availability of planting material at the onset of rains in southern Africa. In some cases, improved sweetpotato germplasm has been lost by smallholder farmers in Mozambique due to prolonged dry spells. Small to medium roots provide an opportunity to conserve germplasm and get planting material at the beginning of the rainy season. The objectives of the study were to (i) measure sprouting ability of diverse germplasm of sweetpotato - farmer varieties, improved clones and released varieties and (ii) estimate their ability to provide planting material for the next crop in southern Mozambique. Trials with 29 genotypes were established in a randomized complete block design with two replications at Umbeluzi Research Station and Nwalate Farm in 2015, 2016 and 2017. At harvest, 14 small to medium roots were selected and stored in small plastic dishes filled with dry sand at Nwalate Farm. After four months in storage, 10 similar roots were taken and planted in 1 m row plots arranged in a randomized complete block design with two replications. The trials were irrigated to initiate sprouting and support plant growth during the first four weeks. Data collected were analysed using SAS 1996. All the tested genotypes sprouted after sowing. The number of sprouts per root were significantly affected by the genotype, location and genotype x location x year interactions. Caelan had the most sprouts per root. Sprout length measured at six weeks after sprouting was also significantly affected by genotype, location, year and genotype x location x year interactions. Caelan had vines each long enough to provide 10 cuttings of 10 cm length for rapid multiplication. The number of cuttings depended on the growth habit of the variety. Irene, a popular variety in Mozambique, is erect and bushy and could only provide four cuttings over the same period. Growth habit especially under a changing climate should be considered in breeding programs as an option of facilitating a sustainable and easy seed system

Genotype × environment interaction and selection for drought adaptation in sweetpotato (Ipomoea batatas [L.] Lam.) in Mozambique

Sweetpotato is grown throughout the year in Mozambique but drought affects storage root yield and biomass productivity. The objectives of this research were to estimate the impact of genotype × environment interactions (G × E) in sweetpotato and select genotypes based on drought indices such as geometric mean, percent yield reduction, drought sensitivity index and harvest index. A total of 58 clones were evaluated during the dry season of 2006, 2008 and 2009. Two treatments were applied for this multi-year trial: full irrigation and without irrigation at the middle of root initiation growth stage. The field layout was a randomized complete block design with three replications. ‘Jonathan’, ‘Resisto’ and ‘Tanzania’ were the check cultivars in each treatment. Storage root and vine yields were recorded at harvest in the trials. Harvest index was computed from the yield data. The analysis of variance, regression and the additive main effects multiplicative interaction (AMMI) analyses, plus phenotypic coefficient of variation and ecovalence were used for dissecting the G × E and assessing the stability of each clone. Treatment, genotype × reatment and genotype year (G × Y) interactions had highest contributions to the variation in storage root yield observed among clones. The stability of harvest index was significantly correlated with the absolute AMMI’s IPCA1 and IPCA2 values for storage root yield. Cultivar performance varied within treatments. Four clones had significantly higher storage root yield (t ha-1 ) than ‘Tanzania’, the best check cultivar under drought. In conclusion, storage root yield (t ha-1 ) was negatively affected by drought and G × Y interaction. Harvest index stability and the geometric mean may be key to identify clones with storage root yield stability and high storage root yield under both treatments. At least two environments should be used at early breeding stages to consider harvest index in the early breeding cycle

Yield, nutritional quality and stability of orangefleshed sweetpotato cultivars successively later harvesting periods in Mozambique

Long-term storage of sweetpotato roots is a great challenge for smallholder farmers in Mozambique. Piecemeal harvesting allows several months supply of roots for household consumption provided weevil infestation is avoided. The objectives of the present studies were to determine yield and changes in key macro- and micronutrients associated with early or late harvesting of orange-fleshed sweetpotato cultivars in Mozambique. Four trials representing harvesting periods of 3, 4, 5 or 6 months after planting were established at Gurue in 2015. The randomized complete block design with three replications was laid in each trial. Yield measurements were done in the field and samples were selected and scanned for dry matter, beta-carotene, iron, zinc and carbohydrate using Near Infrared Spectrometry. Collected data were statistically analysed (SAS 1997 software). Yield, dry matter, starch, iron and beta-carotene increased linearly in some cultivars as time to harvest was prolonged. Iron was not affected by harvesting period. Stability of micronutrients such as iron, zinc and beta-carotene is essential when piecemeal harvesting. The study allowed accurate grouping of the cultivars tested into maturity groups for the first time

Adaptation to mid-season drought in a sweetpotato (Ipomoea batatas [L.] Lam) germplasm collection grown in Mozambique

Drought has negative effects on sweetpotato production. Two experiments with two watering treatments (irrigated and water-stressed) were conducted at Umbeluzi Research Station in 2015. The objectives were to (i) determine response of 48 sweetpotato germplasms to mid-season drought, (ii) determine best traits for improvement of storage root yield under mid-season drought and (iii) assess the selection criteria for identifying drought tolerance in sweetpotato germplasms. The irrigated and water- stressed trials received 640 and 400 mm of water, respectively, throughout the season. Water stress was imposed from 30 to 70 days after planting. Each treatment had two replicates arranged in a randomized complete block design. Data collected on storage root and vine yield and derived drought tolerance indices including harvest index were subjected to analysis of variance in R. Sweetpotato germplasms with high storage root yield under mid-season drought were associated with a high harvest index. Harvest index stability and the geometric mean are key to identifying cultivars with high and stable storage root yield under both treatments. MUSGP0646-126, Irene and Ivone combined both low TOL, SSI, HI and high yield storage root yield across the treatments and over seasons. The use of drought and harvest indices is encouraged for selecting improved cultivars for varied production environments and their regular use in accelerated breeding schemes is suggested

Survival of sweetpotato (Ipomoea batatas [L] Lam) vines in cultivars subjected to long dry spells after the growing season in Mozambique

Optimisation of sweetpotato production potential is not realized in sub-Saharan Africa where dry spells are common after the growing season. Lack of seed cultivars at the beginning of the rainy season is the challenge and identifying those cultivars with the ability to survive a 4 to 7-month dry spell is an important objective in these regions. To this end, the purpose of the present study was to estimate survival of vines of different cultivars under drought stress. Three harvesting times set as 5, 9 and 11 months after planting were established at Umbeluzi, Nwallate and Gurue in 2015. For each harvesting time, 37 clones were evaluated in a randomized complete block design with two replications. Data collected on yield, vine length and number of sprouts were analysed using SAS 1996. Resisto had long stems but no vines after 9 months at any of the sites. The ability of some clones to reach 9 months and 11 months with few vines at Umbeluzi and Nwallate offer sources of planting material for the subsequent season. Sprouting had broad sense heritability above 50%. Sprouting is known to be an important aspect of cultivar survival. While we show that vine length and thickness could be traits responsible for sweet potato drought toleranc